During
World War II, Levi-Montalcini set up a laboratory in her bedroom in Turin and studied the growth of nerve fibers in chicken embryos, discovering that nerve cells die when they lack targets, and laying the groundwork for much of her later research. She described this experience decades later in the science
documentary film Death by Design: The Life and Times of Life and Times (1997). When
Germany invaded Italy in September 1943, her family fled south to
Florence, where they survived
The Holocaust, under false identities, protected by some non-Jewish friends. During the Nazi occupation, Levi-Montalcini was in contact with the partisans of the
Action Party. After the liberation of Florence in August 1944, she volunteered her medical expertise for the
Allied health service, providing critical care to those injured during the war. This period highlighted her resilience and commitment to medical science despite the tumultuous circumstances. Upon returning to Turin in 1945, she resumed her research activities. In September 1946, Levi-Montalcini was granted a one-semester research fellowship in the laboratory of Professor
Viktor Hamburger at
Washington University School of Medicine; he was interested in two of the articles Levi-Montalcini had published in foreign scientific journals. After she duplicated the results of her home laboratory experiments, Hamburger offered her a research associate position, which she held for 30 years. It was there that, in 1952, she did her most important work: isolating
nerve growth factor (NGF) from observations of certain cancerous tissues that cause extremely rapid growth of nerve cells. This crucial finding in biology identified NGF as the main protein responsible for the growth of neurons within the nervous system, allowing for major advances in research. The critical experiment was done with
Hertha Meyer at the Carlos Chagas Filho Biophysics Institute of the
Federal University of Rio de Janeiro in 1952. Their publication in 1954 became the first definitive indication of the protein. By transferring pieces of tumours to chick embryos, Levi-Montalcini established a mass of cells that was full of nerve fibres. The discovery of nerves growing everywhere like a halo around the tumour cells was surprising. When describing it, Levi-Montalcini said it is: "like rivulets of water flowing steadily over a bed of stones." The nerve growth produced by the tumour was unlike anything she had seen before – the nerves took over areas that would become other tissues and even entered veins in the embryo. But nerves did not grow into the arteries, which would flow from the embryo back to the tumour. This suggested to Levi-Montalcini that the tumour itself was releasing a substance that was stimulating the growth of nerves. Her research led to the seminal publication "In vitro experiments on the effects of mouse sarcomas 180 and 37 on the spinal and sympathetic ganglia of the chick embryo" in 1954, which was a foundational work in identifying and understanding
nerve growth factor (NGF). NGF is a critical protein for the growth and maintenance of neurons in the sympathetic and sensory nervous systems, without which brain cells die. This discovery paved the way for future research in neurobiology, demonstrating that the
nervous,
immune and
endocrine systems are linked which had profound implications for understanding neurodegenerative diseases. She was made a full professor in 1958. In 1962, she established a second laboratory in
Rome and divided her time between there and St. Louis. In 1963, she became the first woman to receive the Max Weinstein Award (given by the United Cerebral Palsy Association) due to her significant contributions to neurological research. , 1981 Levi-Montalcini founded the European Brain Research Institute in 2002, and then served as its president. Her role in this institute was at the centre of some criticism from some parts of the scientific community in 2010. Controversies were raised concerning the cooperation of Levi-Montalcini with the Italian pharmaceutical firm Fidia. While working for Fidia, she improved her understanding of
gangliosides. Beginning in 1975, she supported the drug Cronassial (a particular mixture of gangliosides) produced by Fidia from bovine
brain tissue. Independent studies showed that the drug actually could be successful in the treatment of intended diseases (
peripheral neuropathies). Years later, some patients under treatment with Cronassial reported a severe neurological syndrome (
Guillain–Barré syndrome). As per the normal cautionary routine, Germany banned Cronassial in 1983, followed by other countries. Italy prohibited the drug only in 1993; at the same time, an investigation revealed that Fidia paid the Italian Ministry of Health for a quick approval of Cronassial and later paid for pushing the use of the drug in the treatment of diseases where it had not been tested. Levi-Montalcini's relationship with the company was revealed during the investigation, and she was criticized publicly. In the 1990s, she was one of the first scientists to point out the importance of the
mast cell in human pathology. In the same period (1993), she identified the endogenous compound
palmitoylethanolamide as an important modulator of this cell. Understanding this mechanism initiated a new era of research into this compound which has resulted in more discoveries regarding its mechanisms and benefits, a far better understanding of the
endocannabinoid system and new
liposomal palmitoylethanolamide product formulations designed specifically for improved absorption and bioavailability. Levi-Montalcini earned a Nobel Prize along with Stanley Cohen in 1986 in the physiology or medicine category. The two earned their Nobel Prizes for their research into the nerve growth factor (NGF), the protein that causes cell growth due to stimulated nerve tissue. ==Political career==